The use of a spin casting technique in order to form solid components from a liquefied material is generally known in the art as disclosed for example in U.S. Pat. Nos. 4,687,510 and 4,764,212 to Cheney et al. and Okumura. According to the Cheney et al. patent, liquid droplets are cast into solid particles subsequently compacted into a fine powder product. According to the Okumura patent, a liquefied alloy material is cast into powders or membranes which are subsequently sintered or cold pressed into a solid mass product. As to the coating or encapsulation of chemicals within plastic envelopes to form pellets, according to U.S. Pat. No. 4,505,953 to Chen et al., such pellets are intended for dispersion within building materials such as concrete.
The prior art use of spin casting and coating techniques in the manufacture of solid products is well known, as exemplified by the foregoing referred to U.S. patents. Such manufacturing techniques have not however been associated with the formation of solid composite structures having shape-memory properties as disclosed in prior copending application Ser. No. 301,505, now U.S. Pat. No. 5,408,932, with respect to which the present application is related by a common inventor. Such solid composite structures affect the conditions under which casting and coating techniques are practiced, as well as other manufacturing steps associated with such casting and coating techniques.
It is therefore an important object of the present invention to enable formation of composite structures having an increased range of contraction/expansion ratios, capable of being cyclically repeated.
An additional object in accordance with the foregoing object is to provide a relatively low cost, less time consuming method of making a composite structure with a shape-memory capability.